AIM. To resolve conflicting interpretations of data on how proteins in membranes perturb the surrounding lipids and how lipids modulate the function of membrane enzymes, antigens, and receptors; and to produce a definitive book on the subject, fully indexed, to be published within 3 months of the conference. METHOD. The Biophysical Discussions use a unique format whereby (a) the complete texts of all contributions are circulated in advance to all participants; (b) actual meeting time is devoted entirely to discussion (not formal talks); (c) a transcription of plenary debate is made and incorporated into the final book of proceedings. Authors of the 20 plenary papers and 80 posters are selected competitively from abstracts submitted in response to a general international call. Participants are limited to 200. Texts of the papers and 2-page Poster summary texts plus edited transcripts of the debate comprise a 500+-page proceedings book, also published as the January, 1982 issue of the Biophysical Journal, ensuring ease of reference. This conference is third in a series of highly successful Discussions. LONG TERM OBJECTIVES. Membrane phenomena touch a host of medically interesting subjects from cancer to diseases of nerve and blood. The problem in recent years has been burgeoning research results using the many new techniques and machines available, with inadequate communication between researchers whose disciplines have not historically been in close collaboration. For example, physical chemists often don't know enough biology and vice versa to appreciate each other's data. Too often there has been squabbling rather than collaboration. The Organizers hope to utilize the special format of the Discussions to effect communication between practitioners of various techniques. Circulated texts of all papers and posters will enhance such interdisciplinary discussion, since each side has a chance to study the vocabulary as well as the data of the others before the actual conference. This leads to useful (transcribed) exchange.